Tennis: Wawrinka happy to be back, but still feeling pain

Tennis - Australian Open - Hisense Arena, Melbourne, Australia, January 16, 2018. Stan Wawrinka of Switzerland signs autographs after winning against Ricardas Berankis of Lithuania. REUTERS/Toru Hanai

MELBOURNE (Reuters) - Stan Wawrinka feels great to be back after his first-round victory at the Australian Open on Tuesday but is still experiencing pain in the left knee that required surgery last season.

The Swiss former champion, seeded ninth, beat Lithuanian Ricardas Berankis 6-3 6-4 2-6 7-6(2) in his first competitive match for six months to set up a second-round clash with American Tennys Sandgren.